Web services in .NET console and Form

I've encountered the following problem with console applicaiton calling web service. If I call the Web Service asynchronously it works ok as many times as I want. But if I add just the following line Form f = new Form(); - i.e. create a class that is a Form or inherits Form, then the async calls do not work any more - the completion call back is never called. Any suggestions? I'm attaching here a very simple source that reproduces the problem. Note the Form f = new Form line. If I comment it out - then the second call to Web Service returns ok. If is not commented the second call not completed - i.e. the DataCallBack is never called.